Biofilm formation and antimicrobial resistance of uropathogenic Escherichia coli and Klebsiella pneumonia strains isolated from pregnant women in Kerman, Iran

Urinary tract infections are the common medical problems in pregnant women and associated bacteria produce biofilm which protects them from antibiotics. Aim of this study was to determine the pattern of antibiotic resistance and biofilm formation by Escherichia coli and Klebsiellapneumoniae isolated from urine of pregnant women in Kerman, Iran.
Methods and Materials:107 urine samples were collected from pregnant women. Identification was performed by biochemical tests. Antibiotic sensitivity by disc diffusion method and minimum inhibitory concentration (MIC) by agar dilution method were performed. The cell surface hydrophobicity (CSH) behavior of those strains and their ability to form biofilm on glass and propylene surfaces was evaluated in static and shake conditions. The effect of antibiotics on biofilm formation ability was also determined on the catheter surface.

From 80 positive cases, 35 isolates of Escherichia coli and 15 isolates of Klebsiella pneumoniae were selected for this research. The Maximum resistance and sensitivity of isolates were observed about amoxicillin and imipenem, respectively. All isolates with CSH higher than 70% showed better biofilm formation even though on propylene in shaking state. Treatment of culture with 0.5 MIC (µg/ml) and 0.25 MIC (µg/ml) of selected antibiotics significantly reduced the adhesion ability of isolates.

The survey therefore came to the conclusion that similar researches should be continuously repeated in different medical centers to test antimicrobial susceptibility as well as diagnosing and quantifying biofilm infection which surely achieved data help to find appropriate therapeutic way against UTI in pregnancy.